From ac5d9decd2ed57e0569fb8cf0db5cf18a1fa8663 Mon Sep 17 00:00:00 2001
From: Jacek Konieczny <jajcus@jajcus.net>
Date: Fri, 15 Sep 2023 20:04:24 +0200
Subject: [PATCH] linux: preserve existing LD_PRELOAD content

that is needed for Steam overlay and game streaming to work

fixes https://github.com/DFHack/dfhack/issues/3768
---
 docs/about/Authors.rst |  1 +
 docs/changelog.txt     |  1 +
 package/linux/dfhack   | 16 ++++++++--------
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/docs/about/Authors.rst b/docs/about/Authors.rst
index 4b5d4e0c2..e81649d8d 100644
--- a/docs/about/Authors.rst
+++ b/docs/about/Authors.rst
@@ -83,6 +83,7 @@ Herwig Hochleitner      bendlas
 Hevlikn                 Hevlikn
 Ian S                   kremlin-
 IndigoFenix
+Jacek Konieczny         Jajcus
 James                   20k
 James Gilles            kazimuth
 James Logsdon           jlogsdon
diff --git a/docs/changelog.txt b/docs/changelog.txt
index c29879631..6579cf1a8 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -56,6 +56,7 @@ Template for new versions:
 ## New Features
 
 ## Fixes
+- Linux launcher: preserve LD_PRELOAD set by Steam, so Steam Overlay and game streaming works
 
 ## Misc Improvements
 
diff --git a/package/linux/dfhack b/package/linux/dfhack
index a83da71b4..fab3d0602 100755
--- a/package/linux/dfhack
+++ b/package/linux/dfhack
@@ -60,7 +60,7 @@ fi
 case "$1" in
   -g | --gdb)
     shift
-    echo "set exec-wrapper env LD_LIBRARY_PATH='$LD_LIBRARY_PATH' LD_PRELOAD='$PRELOAD_LIB' MALLOC_PERTURB_=45" > gdbcmd.tmp
+    echo "set exec-wrapper env LD_LIBRARY_PATH='$LD_LIBRARY_PATH' LD_PRELOAD='${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB' MALLOC_PERTURB_=45" > gdbcmd.tmp
     gdb $DF_GDB_OPTS -x gdbcmd.tmp --args ./dwarfort "$@"
     rm gdbcmd.tmp
     ret=$?
@@ -95,35 +95,35 @@ case "$1" in
     ;;
   -h | --helgrind)
     shift
-    LD_PRELOAD="$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_HELGRIND_OPTS --tool=helgrind --log-file=helgrind.log ./dwarfort "$@"
+    LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_HELGRIND_OPTS --tool=helgrind --log-file=helgrind.log ./dwarfort "$@"
     ret=$?
     ;;
   -v | --valgrind)
     shift
-    LD_PRELOAD="$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_VALGRIND_OPTS --log-file=valgrind.log ./dwarfort "$@"
+    LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_VALGRIND_OPTS --log-file=valgrind.log ./dwarfort "$@"
     ret=$?
     ;;
   -c | --callgrind)
     shift
-    LD_PRELOAD="$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_CALLGRIND_OPTS --tool=callgrind --separate-threads=yes --dump-instr=yes --instr-atstart=no --log-file=callgrind.log ./dwarfort "$@"
+    LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" setarch "$setarch_arch" -R valgrind $DF_CALLGRIND_OPTS --tool=callgrind --separate-threads=yes --dump-instr=yes --instr-atstart=no --log-file=callgrind.log ./dwarfort "$@"
     ret=$?
     ;;
   --strace)
     shift
-    strace -f setarch "$setarch_arch" -R env LD_PRELOAD="$PRELOAD_LIB" ./dwarfort "$@" 2> strace.log
+    strace -f setarch "$setarch_arch" -R env LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" ./dwarfort "$@" 2> strace.log
     ret=$?
     ;;
   -x | --exec)
-    exec setarch "$setarch_arch" -R env LD_PRELOAD="$PRELOAD_LIB" ./dwarfort "$@"
+    exec setarch "$setarch_arch" -R env LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" ./dwarfort "$@"
     # script does not resume
     ;;
   --sc | --sizecheck)
     PRELOAD_LIB="${PRELOAD_LIB:+$PRELOAD_LIB:}./hack/libsizecheck.so"
-    MALLOC_PERTURB_=45 setarch "$setarch_arch" -R env LD_PRELOAD="$PRELOAD_LIB" ./dwarfort "$@"
+    MALLOC_PERTURB_=45 setarch "$setarch_arch" -R env LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" ./dwarfort "$@"
     ret=$?
     ;;
   *)
-    setarch "$setarch_arch" -R env LD_PRELOAD="$PRELOAD_LIB" ./dwarfort "$@"
+    setarch "$setarch_arch" -R env LD_PRELOAD="${LD_PRELOAD:+$LD_PRELOAD:}$PRELOAD_LIB" ./dwarfort "$@"
     ret=$?
     ;;
 esac